Telephonic receiver



UNITED STATES PATENT OFFICE.

J. MILTON STEARNS, JR, OF BROOKLYN, New YORK.

TELEPHIONIC RECEIVER.

I SPECIFICATION forming part of Letters Patent No. 248,117, dated October 11, 1881.

Application filed June 6, 1 881. (No model.)

To all whom it may concern Be it known that I, J. MILTON STEARNS, Jr., of the city of Brooklyn,.in the county of Kings and State of New York, have invented an Improvement in Telephonic Receivers, of which the following is a specification.

My invention relates to an improvement upon what is known as the lteissreceivingtelephone; and it consists in forming the core with wedge-shaped grooves or threads, either spirally, like a screw, or in rings; further, in securing said core into a block of wood or other material and arranging the coil about it; further, in covering said core and coil with a sounding-box; and, finally, arranging said receiver in connection with an induction-coil, all of which is fully set forth in the following specification, and shown in the accompanying drawing, which forms part thereof.

The object of this invention is the construction of a simple, cheap, and durable commercial telephonic receiver. I

The drawing represents my improved telephone. (part in section) as arranged with the induction-coil and line.

In the drawing, A is the receiver-coil, and is arranged about the core B of soft iron, and

by which it may be secured to the block of wood D. This core, as shown, is simply a large wood-screw, the screw-threads of which form the wedge-shaped grooves or spirals 0. One

' terminal of the coil A is connected with the and the sound emitted by the lengthening and shortenin g of the core is greatly increased, and is made distinctly audible by means of the sou n din g-box E, arranged over the instrument.

I do not limit myself to the shape of the spirals or grooves; but in practice I prefer sharp,

deep threads, and tolerably near to each other.

Having now described my invention, whatI claim as new, and desire to secure by Letters Patent, is-

1. A core of a telephone-receiver magnet provided with threads cu'tthereon and arranged circumferentially or spirally about said core, in combination with a helix and its bobbin, the outer edge of the thread being only in contact with the bobbin of said helix, substantially as and for the purpose specified.

2. A telephonereceiver consisting of the core B, provided with threads 0, block D, coil A, arranged about said core and clamped by it firmly to the block D, and sounding-box E without a diaphragm, as and for the purpose specified.

3. A telephone-receiver consisting of the core 13, provided with threads C out thereon, coil A, arranged about said core and clamped rigidlytotheblockl),aud sounding-boxEwithout a diaphragm, in combination with circuit v I, in connection with the primary wire of the induction-coil H, the tine wire or secondary coil of same being in circuit with the line and ground, substantially-as and for the purpose specified. I

In testimony of which invention I hereunto set my hand.

J. MILTON STEARNS, JR.

Witnesses:

J OHN M. STEARNS, GEO. W. GREEN. 

